I've had an O.S. .46FX and currently have a Magnum .52XLS (2 stroke ) in mine. (Had to open up the engine bearers a bit for the .52 )
Any decent BB .46 like the O.S. or Thunder Tiger, Magnum, etc. is PLENTY of power. Mine will flutter the rudder while going vertical if I don't watch out...[X(]
Check out the Profile forum...do a search and you'll find a lot of info in the Tribute.
There are several mods that really should be done if you want it to live very long.

Just a couple:
I bolted AND glued the wing and canopy section on to stiffen the fuselage. (the fuse usually cracks on the bottom, just under the trailing edge of the wing )

I put taller and stiffer landing gear on mine (from a Morris the Knife )